EP1247571A1 - New fibre containing active elements, process for the preparation thereof and their uses, in particular in packaging - Google Patents

Abstract

A material suitable for forming elements intended for packaging, olfactory supports, industrial packaging, decorative materials, odor and humidity absorbers etc, consisting of a matrix containing a porous absorbent support capable of creating cavities open at least in part to the surface of the material and capable or absorbing and releasing evenly over time an active principle or principles. <??>An Independent claim is also included for a method of making the material in such a way that the fibers can be entirely or virtually entirely free by desorption of the active principle, allowing reuse of the material for a different purpose with a different active principle.

Description

Technical sector of the invention:

The present invention relates to the technical sector of products and elements that can be used as packaging, after together and for simplicity, including in the claims, "Packaging".

The invention relates more particularly to the technical sector of the elements or products of this type (hereinafter together, for simplicity, including in the claims, “elements”) presenting functions of the “active” type or "smart" as explained below.

Technical problem:

In the food industry, packaging materials have experienced these last years an exponential evolution in terms of solutions made for the conservation of perishable foodstuffs. Among the innovations recent, there is a growing interest in the manufacture of so-called packaging "Intelligent". These are products intended to contain food perishable, and one or more functionalities are associated with these products. For this, the constituent material has a predetermined reaction to a change in the state of the environment of the packaged product. As example, we can cite packaging films which absorb oxygen may accidentally come into contact with the product, in order to preserve this too rapid oxidation. Other similar functions are performed; like salting out by the packaging film of compounds bactericides thus preventing degradation.

• Les produits actifs que doivent diffuser les emballages sont souvent des molécules organiques qui se dégradent facilement aux températures de mise en oeuvre des polymères. Il est donc difficile de les incorporer au cours de la production de l'emballage lui-même.
• La vitesse de diffusion est généralement mal maítrisée, de même que la concentration du produit relargué.

The main difficulties slowing the imagination of designers lie in the following points:

• The active products which the packaging must diffuse are often organic molecules which are easily degraded at the temperatures of processing of the polymers. It is therefore difficult to incorporate them during the production of the packaging itself.
• The speed of diffusion is generally poorly controlled, as is the concentration of the product released.

An object of the invention is to propose elements, in particular in synthetic or plastic material having such functionality.

• capacité à incorporer et diffuser une ( ou plusieurs ) substance active par rétention ou re largage d'un composé dont la stabilité thermique est pourtant faible.
• possibilité d'utiliser la totalité de la substance active ou du principe actif et de recharger le produit de nombreuses fois pour des usages successifs identiques ou non (changement ou non de principe actif).
• maítrise de la quantité et de la vitesse de re largage du principe actif.
• recyclabilité totale du produit.

The targeted elements must have the following properties:

• ability to incorporate and diffuse one (or more) active substance by retention or release of a compound whose thermal stability is however low.
• possibility of using all of the active substance or of the active principle and of recharging the product many times for successive uses, identical or not (change or not of active principle).
• control of the quantity and speed of release of the active ingredient.
• total recyclability of the product.

Prior art :

Besides the functions of shape, color and mechanical strength, conventionally made to plastic objects, others are more specific, such as UV or fire resistance. These functions are obtained by incorporation into the polymer of one or several chemicals that must change their behavior towards of a change in his environment. In all the cases cited, the behavior of the object is "static" and the incorporated additive acts only in the event of external solicitation.

There are some cases in which the reaction of the object on the environment is spontaneous, and we can cite as an example the diffusion of perfumes, insecticides ... with plastic supports soaked with active products during of their manufacture. In this case, the dissemination of the product is only very bad controlled and, taking into account the effects of surface concentration, it varies from over time.

In all cases, the active additives are added to the polymer during the manufacture of the material or at best of the object, that is to say that the product must be stable at polymer transformation temperatures. This fact limits the technique using mineral or organic products which are not very mobile, therefore weak diffusion effect. In addition, we are obliged to process the entire polymer, therefore of the object, which causes the presence of active ingredient in core thickness, product which will therefore remain definitively unused due to its unavailability at the surface or in close proximity to the surface.

Another major drawback of the current technique is that objects become permanently inactive after exhaustion of the product broadcasting. In addition, the residual content of active ingredient remained trapped in the heart of matter, as we have just seen, poses ecological problems for the eventual recycling of the object, without naturally counting the loss generally expensive active ingredient material.

We have already tried to get around these drawbacks by depositing on the surface of the object the active principle, either directly or in the soaked or incorporated state in a holder. Unfortunately this technique is not reliable because the less friction with the surface leads to accidental consumption of the active product.

There is therefore an important and recognized need for a material capable of form diffusing elements in which one could easily incorporate at least one active principle (or a precursor substance thereof active ingredient, below, including in the claims, "active ingredient", the singular also includes the plural, as will be easily understood those skilled in the art), from which said active ingredient could diffuse controlled manner as a function of time, in whole or essentially in totality (i.e. with very little residual active ingredient in the matrix of material, when the functionality of the active ingredient has reached a level such that the diffuser element must be replaced or recharged, as will be seen below), that we can preferably recharge without difficulty, and which does not impose denaturing constraints on the active ingredient, such as thermal or other constraints.

Summary of the invention:

In its most general aspect, the present invention is characterized by a material (this term including any structure, simple or composite, suitable for form or generate said elements described below) capable of forming elements of any shape and destination, in particular, but not restrictive, for packaging, olfactory supports, industrial packaging, decoration materials, odor or moisture absorbers or others substances, and analogous products, into which at least one absorbent support of the porous type capable of creating cavities opening to the less partially on the surface of said material, cavities which are capable of accommodating an effective amount of active ingredient by absorption and to release a dose effective and substantially regular, over time, of said active ingredient.

It is recalled that "active ingredient" covers, including in the claims not only the active ingredient itself but also a precursor of this active ingredient, or possibly a product or substance itself capable of releasing said active principle, as well as the mixtures, associations, combinations, such "active ingredients", as well functionality (e.g. combination of scents) or functionality different (for example a perfume and a deodorant or anti-acariene substance, etc ...) and analogous variants which will appear clearly to humans without having to specify it again.

The invention also relates to the process for manufacturing this material, as well as its applications, and also concerns the "elements" formed in said material (or at least partially comprising said material), as well as applications of these elements, already mentioned or suggested above.

• le surcoût car il faut ajouter un produit dans toute la masse du matériau,
• risque que les pores soient complètement bouchés par la matière plastique lors de toute transformation.
• risque qu'une trop faible proportion de « cavités » s'ouvre sur la surface.
• risque d'affaiblir les propriétés mécaniques de la matrice de par la présence d'hétérogénéités dans sa masse.
• obligation de disposer d'un volume « réservoir » important, et donc d' une grande quantité d'absorbant, avec un risque accru de dégrader les propriétés du matériau.
• impossibilité de prévoir les caractéristiques de diffusion, notamment une diffusion régulière et reproductible.

This solution has never been considered, perhaps due to the following obvious prejudices:

• the additional cost because it is necessary to add a product throughout the mass of the material,
• risk that the pores are completely blocked by the plastic during any transformation.
• risk that too small a proportion of "cavities" will open on the surface.
• risk of weakening the mechanical properties of the matrix due to the presence of heterogeneities in its mass.
• obligation to have a large "reservoir" volume, and therefore a large amount of absorbent, with an increased risk of degrading the properties of the material.
• impossibility of predicting the characteristics of diffusion, in particular a regular and reproducible diffusion.

According to the invention, it has been shown that all the problems can be solved of the prior art, and get around the prejudices that seemed insurmountable, by a process by which one uses to manufacture "elements", or it is incorporated into these "elements", and this from the manufacture of said "Elements", including packaging, absorbent material and releasing an active ingredient, said active ingredient itself being added during a later stage of manufacture or during use.

Detailed description of the invention:

According to a preferred embodiment, said material is made, in what relates to its matrix, a plastic material or a mixture of such plastics, especially polymers or copolymers.

By way of non-limiting example of such a matrix, mention will be made of all the (co) polymers capable of to form flexible films or to be otherwise shaped, as under form of plates, flat surfaces or not.

All polymers can be suitable, whether they are thermoplastic or thermosets. The so-called convenience thermoplastics (Polyethylene, Polystyrene, Polypropylene) and unsaturated polyesters are particularly suitable because of their processing conditions, especially relatively low processing temperature, preserving the integrity of the absorbent support, in particular natural fibers, but also because they are the most used materials in the targeted applications.

• polyoléfines : polyéthylènes, polypropylènes, polyisobutylène, polyméthylpentène,
• polychlorures de vinyle
• polyacétates de vinyle et acétates polyvinyliques
• polymères styréniques: PS (polystyrène), ABS (acrylonitrile butadiène styrène), SB (styrène-butadiène), SAN (styrène acrylonitrile), ASA (acrylonitrile styrène acrylates)
• polyacétals : POM ( polyoxyméthylène)
• polyesters saturés et insaturés
• polyépoxydes
• aminoplastes : MF (mélamineformaldéhyde), UF (urée formaldéhyde)
• polymères phénoliques
• silicones
• polyuréthanes
• polyamides : 6, 6-6, 4-6, 6-12, 6-10, 11, 12 et aromatiques
• polymères acryliques
• polymères cellulosiques
• polycarbonates
• polymères fluorés: PVDF (fluorure de vinylidène), PEP ( (polyéthylènepropylène) perfluoré), ETFE (ethylène tétrafluoroéthylène), PCTFE (polychlorotrifluoroéthylène)

et analogues bien connus de l'homme de métier,
et de manière générale tout matériau pouvant être mis en forme à une température inférieure à 350 °C environ, et susceptible de voir ses propriétés renforcées par l'addition de fibres naturelles: béton, bitume, métaux à bas point de fusion, poudres céramiques comprimées, polymères naturels comme amidon, cellulose, et leurs dérivés et analogues connus de l'homme du métier.The following (co) polymers will be mentioned in particular:

• polyolefins: polyethylenes, polypropylenes, polyisobutylene, polymethylpentene,
• polyvinyl chloride
• polyvinyl acetates and polyvinyl acetates
• styrenic polymers: PS (polystyrene), ABS (acrylonitrile butadiene styrene), SB (styrene-butadiene), SAN (styrene acrylonitrile), ASA (acrylonitrile styrene acrylates)
• polyacetals: POM (polyoxymethylene)
• saturated and unsaturated polyesters
• polyepoxides
• aminoplasts: MF (melamine formaldehyde), UF (formaldehyde urea)
• phenolic polymers
• silicones
• polyurethanes
• polyamides: 6, 6-6, 4-6, 6-12, 6-10, 11, 12 and aromatic
• acrylic polymers
• cellulosic polymers
• polycarbonates
• fluorinated polymers: PVDF (vinylidene fluoride), PEP ((polyethylenepropylene) perfluorinated), ETFE (ethylene tetrafluoroethylene), PCTFE (polychlorotrifluoroethylene)

and analogues well known to those skilled in the art,
and in general any material that can be shaped at a temperature below about 350 ° C, and likely to have its properties enhanced by the addition of natural fibers: concrete, bitumen, metals with low melting point, compressed ceramic powders , natural polymers such as starch, cellulose, and their derivatives and analogues known to those skilled in the art.

Among the absorbent supports which may be suitable, there are fibers natural. These can indeed be incorporated into polymers in order to for example to strengthen their mechanical properties. The object made in polymer then has a surface at which a number of the fibers incorporated. Due to their tubular structure, fibers are able to absorb and store a significant amount of a any fluid.

By way of example, there is shown in the single appended figure a water absorption and desorption cycle by a polyester sheet unsaturated containing hemp fibers at 30% by weight. The plate is first immersed in water and then left in ambient air (23 ° C and 93% RH). Those skilled in the art will understand that the interesting part of the cycle concerns the first days during which the slope of the curve is maximum and practically constant. When the plateau is reached (after about 15 days in this nonlimiting case), the speed of diffusion becomes too weak to be of interest. In the case of a need for protection on shorter or longer duration, the skilled person will be able to consider a modification of the diffusion rate by alterations in viscosity, surface tension, and other known parameters of the fluid, and / or the closing the packaging.

All natural fibers are possible: hemp, flax, sisal, straws, jute, cotton, wood ... but we can also use porous products any like for example diatomaceous earth or spheres of crushed glass which as a mineral filler has the advantage of endure high temperatures.

Natural fibers can be used in various forms geometric, in thermoplastic applications they will be chosen from a length less than 30 or 40 mm, preferably less than 20 mm in order to do not disturb the injection or extrusion processes. Their concentration will be adjusted by the skilled person according to the mechanical properties to reach and the quantity of active ingredient to be incorporated, its general knowledge and some simple routine tests, eventually.

• les fibres sont des additifs de renforcement , et leur introduction dans les plastiques améliore les propriétés mécaniques de ceux ci. Elles sont d'un coût modeste et, étant de faible densité (deux fois plus faible que le verre), un petit pourcentage pondéral occupe un grand volume.
• les fibres ont une structure creuse et avec les procédés de transformation on obtient une quantité reproductible de fibres émergeant en surface, cette quantité étant proportionnelle ou sensiblement proportionnelle à la quantité totale de fibres introduites.
• les fibres émergeant en surface se comportent comme des capillaires capables d'accueillir un fluide. Les dimensions des cavités ou pores ainsi créés sont suffisantes pour permettre au principe absorbé d'être relargué par le simple gradient de concentration avec l'extérieur. Il est à noter que dans le cas du verre les espaces capillaires entre les fibres et la matrice polymère permettent l'adsorption d'un fluide mais pas sa diffusion compte tenu de la faible dimension des cavités.
• le phénomène d'absorption / désorption d'un fluide quelconque est reproductible indéfiniment.
• les fibres peuvent être entièrement ou sensiblement entièrement débarrassées (à la désorption) du principe actif absorbé, autorisant ainsi une optimisation de l'emploi du principe actif ainsi qu'un recyclage du matériau ou de l'élément (il suffit de recharger l'élément en principe actif) ou sa réutilisation dans une autre fonction apportée par un principe actif différent. De même on peut utiliser simultanément plusieurs composés ou principes actifs diffusants. Dans tous les cas les composés n'ont pas à avoir d'affinité ou de compatibilité avec la matrice de polymère car ils n'entrent pas à son contact, puisqu'ils sont confinés dans la fibre.

The use as absorbent of natural fibers makes it possible to solve all the aforementioned problems:

• fibers are reinforcing additives, and their introduction into plastics improves their mechanical properties. They are of modest cost and, being of low density (twice less than glass), a small percentage by weight occupies a large volume.
• the fibers have a hollow structure and with the transformation processes a reproducible quantity of fibers emerging on the surface is obtained, this quantity being proportional or substantially proportional to the total quantity of fibers introduced.
• the fibers emerging on the surface behave like capillaries capable of receiving a fluid. The dimensions of the cavities or pores thus created are sufficient to allow the absorbed principle to be released by the simple concentration gradient with the outside. It should be noted that in the case of glass the capillary spaces between the fibers and the polymer matrix allow the adsorption of a fluid but not its diffusion taking into account the small dimension of the cavities.
• the absorption / desorption phenomenon of any fluid is reproducible indefinitely.
• the fibers can be entirely or substantially entirely freed (on desorption) of the absorbed active principle, thus allowing optimization of the use of the active principle as well as recycling of the material or of the element (it suffices to reload the element active ingredient) or its reuse in another function provided by a different active ingredient. Likewise, several diffusing compounds or active principles can be used simultaneously. In all cases, the compounds do not have to have affinity or compatibility with the polymer matrix because they do not come into contact with it, since they are confined in the fiber.

Naturally, however, compatible active ingredients will be used with the matrix.

• En variant la nature du fluide (sa viscosité ou son affinité pour la fibre entre autres) on va faire varier la vitesse de relargage.
• En faisant varier la concentration de principe actif dans la fibre, on fera varier de même la concentration en produit diffusé.
• En faisant varier la teneur en fibres du support polymère, on fera varier aussi la concentration du diffusant, mais on aura aussi une quantité de principe actif disponible plus ou moins grande.
• On peut enfin faire varier de la même manière la quantité globale de principe actif à diffuser en laissant le matériau immergé plus ou moins longtemps dans le fluide.

One can also consider filling the capillaries (incorporated fibers) with a fluid whose viscosity or surface tension or any other parameter prohibits its subsequent diffusion. A functionalized product is thus obtained after its manufacture, therefore the possibility of using an agent with very low thermal stability.
Several parameters of incorporation are easily adjustable, in particular if a solvent-based fluid containing said active principle is considered as active ingredient:

• By varying the nature of the fluid (its viscosity or its affinity for the fiber among others), the release rate will be varied.
• By varying the concentration of active ingredient in the fiber, the concentration of diffused product will also be varied.
• By varying the fiber content of the polymer support, the concentration of the diffusing agent will also be varied, but there will also be a greater or lesser amount of active ingredient available.
• Finally, the overall quantity of active principle to be diffused can also be varied in the same way by leaving the material immersed for more or less time in the fluid.

• protection contre les bactéries, les acariens, les insectes, les moisissures ...
• accélération ou ralentissement du mûrissement ...
• absorption ou émission de gaz fonctionnels ...
• maintien d'une atmosphère particulière (ex : humidité)
• absorption de l'humidité (emploi d'un superabsorbant pour mouiller les fibres), etc....

The manufacture of elements of all kinds in polymers (or other type of matrix) loaded with natural fibers therefore allows the production of functionalized industrial products, and in particular of functional packaging. It suffices to immerse the material, or the complete element, in an active principle or in a fluid containing said active principle, or to process the finished industrial product, in particular the packaging, so that the latter becomes multi-functional. The list of functions brought to the packaging by the active substances is not limited, nor is the list of applications.
In the food sector, which represents significant potential although not the only application, we can consider creating packaging, among other things, with the following functions:

• protection against bacteria, mites, insects, molds ...
• acceleration or slowing down of ripening ...
• absorption or emission of functional gases ...
• maintenance of a particular atmosphere (eg humidity)
• moisture absorption (use of a superabsorbent to wet the fibers), etc ...

One of the major advantages of the process is the possibility of repeating the phenomenon of recirculation or recycling of the elements, in particular packaging, functionality being sort of "regenerated" by a new treatment of the element. We can even consider that the same element, in particular a packaging, can in successive stages perform different functions through treatment with substances different assets.

Finally, suitable immersion in a neutral solvent eliminates any trace of active substance, therefore to regenerate an element, in particular packaging, inactive and therefore ready for new use.

According to a preferred embodiment, the matrix loaded with fibers, preferably natural, must contain at least 5 to 10% by weight, or better at at least 20% of matrix, in particular of polymer matrix.

Regarding the case of a polymer matrix, and whatever the type of (co) polymer used, the conventional “compounding” processes (that is to say of the fibrous filler with the polymer) can be used for the incorporation of fibers, and do not present any difficulty special.

The active principle can be introduced in liquid or even gaseous form or still solid, and in the latter two cases it is better to use a liquid solution of the active ingredient (s).

The liquid will have characteristics (viscosity, surface tension, concentration ...) which allow to adjust its diffusion speed. It could be introduced into the porosities of the object by any means such as soaking, spraying, wiping ....

These processes can optionally be carried out at pressures and temperatures different from standard conditions (# 20 ° C, 1 atm) in order to facilitate penetration by absorption and / or capillarity.

We can consider treating in the manner described above all of element or parts only, using techniques usual plastics for the realization of multi-material objects.

• Emballages agro-alimentaires: diffusion de produits bactéricides, fongicides, insecticides, d'agents de mûrissement, d'atmosphères protectrices, absorption ou désorption d'eau...
• Conditionnements industriels: relargage de produits de protection, antirouille, contrôle de l'humidité..
• Produits grand public : pièces utilitaires ou simples supports pour la diffusion d'agents antibactérien, antiacarien, antifongique..., insecticide, déodorant, désinfectant, odorant, parfum, ..., comme filtres pour aspirateurs, éléments de systèmes de climatisation et traitement de l'air du bâtiment ou des transports, poubelles ou sacs poubelle, supports olfactifs et objets de « marketing olfactif » comme des jouets olfactifs, matériaux de décoration parfumés ou de contrôle de l'humidité, ou insecticides, déodorants, anti-tabac,
• Emballages divers: contrôle de l'humidité, absorbeurs d'oxygène, diffusion de produits bactéricides, fongicides, insecticides, d'agents de mûrissement, d'atmosphères protectrice,...

The applications of the invention are extremely numerous, by way of examples:

• Food packaging: diffusion of bactericidal products, fungicides, insecticides, ripening agents, protective atmospheres, water absorption or desorption ...
• Industrial packaging: release of protective products, anti-rust, humidity control, etc.
• Consumer products: utility parts or simple supports for the diffusion of antibacterial, anti-mite, antifungal agents, insecticide, deodorant, disinfectant, odorant, perfume, ..., as filters for vacuum cleaners, elements of air conditioning systems and treatment building or transport air, garbage cans or garbage bags, olfactory supports and "olfactory marketing" objects such as olfactory toys, perfumed decoration materials or humidity control, or insecticides, deodorants, anti-tobacco,
• Various packaging: humidity control, oxygen absorbers, diffusion of bactericidal products, fungicides, insecticides, ripening agents, protective atmospheres, ...

It is recalled that "active ingredient" covers, including in the claims not only the active ingredient itself but also a precursor of this active ingredient, or possibly a product or substance itself capable of releasing said active principle, as well as the mixtures, associations, combinations, such "active ingredients", as well functionality (e.g. combination of scents) or functionality different (for example a perfume and a deodorant or anti-mite substance, etc ...) and analogous variants which will appear clearly to humans without having to specify it again.

The invention also covers all the embodiments and all the applications that will be directly accessible to the skilled person at the reading of this application, of his own knowledge, and possibly simple routine tests.

Claims (18)

Material, this term including any structure, simple or composite, capable of forming or generating said elements described below, capable of forming elements of any shape and destination, in particular, but not limited to, for packaging, olfactory supports, packaging industrial, decorative materials, absorbers of odors or humidity or other substances, and similar products, characterized in that it consists of a matrix into which is introduced or loaded at least one absorbent support of the porous type capable of creating cavities opening at least partially on the surface of said material, cavities which are capable of accommodating an effective quantity of active principle by absorption and of releasing an effective and substantially regular dose, over time, of said active principle. Material according to claim 1 characterized in that the "active ingredient" is chosen from the active ingredient itself, a precursor of this active ingredient, or a product or substance itself capable of releasing said active ingredient, as well as the mixtures , associations, combinations, such “active ingredients”, of the same functionality as combinations of perfumes or of different functionalities such as a perfume and a deodorant or anti-mite substance. Material according to claim 1 or 2 characterized in that its matrix consists of a plastic material or a mixture of such plastic materials, in particular polymers or copolymers, all of which (co) polymers capable of forming flexible films or to be otherwise shaped, as in the form of plates, flat surfaces or not, and in that preferably the loaded matrix confides at least 5 to 10% by weight, or better at least 20% of matrix, in particular of matrix polymer. Material according to claim 3 characterized in that said polymers are thermoplastic or thermosetting, like so-called convenience thermoplastics (Polyethylene, Polystyrene, Polypropylene) and unsaturated polyesters, and are in particular chosen from the following: polyolefins: polyethylenes, polypropylenes, polyisobutylene, polymethylpentene, polyvinyl chloride polyvinyl acetates and polyvinyl acetates styrenic polymers: PS (polystyrene), ABS (acrylonitrile butadiene styrene), SB (styrene-butadiene), SAN (styrene acrylonitrile), ASA (acrylonitrile styrene acrylates) polyacetals: POM (polyoxymethylene) saturated and unsaturated polyesters polyepoxides aminoplasts: MF (melamine formaldehyde), UF (urea formaldehyde) phenolic polymers silicones polyurethanes polyamides: 6, 6-6, 4-6, 6-12, 6-10, 11, 12 and aromatic acrylic polymers cellulosic polymers polycarbonates fluorinated polymers: PVDF (vinylidene fluoride), PEP ((polyethylenepropylene) perfluorinated), ETFE (ethylene tetrafluoroethylene), PCTFE (polychlorotrifluoroethylene) and in general any material that can be shaped at a temperature below about 350 ° C, and likely to have its properties enhanced by the addition of natural fibers: concrete, bitumen, metals with low melting point, compressed ceramic powders , natural polymers like starch, cellulose. Material according to any one of Claims 1 to 4, characterized in that the absorbent supports are natural fibers or any porous products such as diatomaceous earth or ground glass spheres. Material according to claim 5 characterized in that the fibers are chosen from: hemp, linen, sisal, kenaf, jute, cotton, wood, straws. Material according to claim 5 or 6 characterized in that natural fibers are used in various geometric forms such as, in thermoplastic applications, of a length less than 30 or 40 mm, preferably less than 20 mm. Process for manufacturing materials according to any one of Claims 1 to 7, characterized in that at least one absorbent support of the porous type is incorporated in a matrix capable of creating cavities opening at least partly on the surface of said material, cavities which are capable of accommodating an effective quantity of active principle by absorption and of releasing an effective and substantially regular dose, over time, of said active principle. Process according to Claim 8, characterized in that the matrix consists of a plastic material or a mixture of such plastic materials, in particular polymers or copolymers, all of which (co) polymers capable of forming flexible films or of being otherwise shaped, such as in the form of plates, flat surfaces or not. Process according to Claim 9, characterized in that the said polymers are thermoplastic or thermosetting, like the so-called convenience thermoplastics (Polyethylene, Polystyrene, Polypropylene) and the unsaturated polyesters, and are in particular chosen from the following: polyolefins: polyethylenes, polypropylenes, polyisobutylene, polymethylpentene, polyvinyl chloride polyvinyl acetates and polyvinyl acetates styrenic polymers: PS (polystyrene), ABS (acrylonitrile butadiene styrene), SB (styrene-butadiene), SAN (styrene acrylonitrile), ASA (acrylonitrile styrene acrylates) polyacetals: POM (polyoxymethylene) saturated and unsaturated polyesters polyepoxides aminoplasts: MF (melamine formaldehyde), UF (urea formaldehyde) phenolic polymers silicones polyurethanes polyamides: 6, 6-6, 4-6, 6-12, 6-10, 11, 12 and aromatic acrylic polymers cellulosic polymers polycarbonates fluorinated polymers: PVDF (vinylidene fluoride), PEP ((polyethylenepropylene) perfluorinated), ETFE (ethylene tetrafluoroethylene), PCTFE (polychlorotrifluoroethylene) and in general any material that can be shaped at a temperature below about 350 ° C, and likely to have its properties enhanced by the addition of natural fibers: concrete, bitumen, metals with low melting point, compressed ceramic powders , natural polymers like starch, cellulose. Process according to any one of Claims 8 to 10, characterized in that the absorbent supports are natural fibers or any porous products such as, for example, diatomaceous earth or ground glass spheres, in that the fibers are chosen from: hemp, linen, sisal, kenaf, jute, cotton, wood, straws, in that natural fibers are used in various geometric forms such as, in thermoplastic applications, of a length less than 30 or 40 mm, preferably less than 20 mm. Process according to any one of Claims 8 to 11, characterized in that the fibers can be entirely or substantially entirely freed, on desorption, of the absorbed active principle, thus allowing optimization of the use of the active principle as well as recycling of the material or element or its reuse in another function provided by a different active principle, or it is possible to use simultaneously several diffusing compounds or active principles, and preferably active principles compatible with the matrix. Process according to any one of Claims 8 to 12, characterized in that in the case of a polymer matrix, and whatever the type of (co) polymer used, the conventional "compounding" processes, that is to say - say mixing the fibrous filler with the polymer, can be used for incorporating fibers or porous material. Process according to any one of Claims 8 to 13, characterized in that the active principle can be introduced in liquid or even gaseous or even solid form, and in these two cases it is preferable to use a liquid solution of the principle or principles active, the liquid having characteristics (viscosity, surface tension, concentration ...) which make it possible to adjust its speed of diffusion and which can be introduced into the porosities of the object by any means such as soaking, spraying, wiping, these processes possibly being able to be carried out at pressures and temperatures different from standard conditions (# 20 ° C, 1 atm) in order to facilitate penetration by absorption and / or capillarity, and are treated in the manner described above. 'the whole element or some parts only, using the techniques of plastics processing for the realization of multi-material objects. Process according to any one of Claims 8 to 14, characterized in that the capillaries (incorporated fibers) are filled with a fluid whose viscosity or surface tension or any other parameter prohibits its subsequent diffusion. Materials characterized in that they have been prepared by a process according to any one of Claims 8 to 15, in particular unsaturated polyester sheet containing hemp fibers at 30% by weight, the sheet having first been immersed in the water then left in the ambient air (23 ° C and 93% RH), and in that one optionally operates a modification of the diffusion rate of the fluid by alterations of the viscosity, surface tension, and other parameters known to the fluid, and / or the closure of the packaging, several parameters of the incorporation being easily adjustable, in particular if a solvent-based fluid containing said active ingredient is considered as active ingredient: By varying the nature of the fluid (its viscosity or its affinity for the fiber among others), the release rate will be varied. By varying the concentration of active ingredient in the fiber, the concentration of diffused product will also be varied. By varying the fiber content of the polymer support, the concentration of the diffusing agent will also be varied, but there will also be a greater or lesser amount of active ingredient available. Finally, the overall quantity of active principle to be diffused can also be varied in the same way by leaving the material immersed for more or less time in the fluid. Materials according to any one of claims 1 to 7 and 16 or prepared according to any one of claims 8 to 15 characterized in that an appropriate immersion is carried out in a neutral solvent which makes it possible to remove any trace of active substance, therefore to regenerate said material, in particular a packaging, in the inactive state and therefore ready for a new use. Applications of the materials according to any one of Claims 1 to 7 or 16 or prepared according to any one of Claims 8 to 15 or of the methods according to any one of Claims 8 to 16 in the following fields: Food packaging: distribution of bactericidal products, fungicides, insecticides, ripening agents, protective atmospheres, absorption or desorption of water ... in particular packaging with the following functions: protection against bacteria, mites, insects, molds ... acceleration or slowing down of ripening ... absorption or emission of functional gases ... maintenance of a particular atmosphere (eg humidity) moisture absorption (use of a superabsorbent to wet the fibers), etc ... Industrial packaging: release of protective products, anti-rust, humidity control, etc. Consumer products: utility parts or simple supports for the diffusion of antibacterial, anti-mite, antifungal agents, insecticide, deodorant, disinfectant, odorant, perfume, ..., as filters for vacuum cleaners, elements of air conditioning systems and treatment building or transport air, garbage cans or garbage bags, olfactory supports and "olfactory marketing" objects such as olfactory toys, perfumed decoration materials or humidity control, or insecticides, deodorants, anti-tobacco, Various packaging: humidity control, oxygen absorbers, diffusion of bactericidal products, fungicides, insecticides, ripening agents, protective atmospheres, ...

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